Display module encapsulation structure and preparation method thereof

ABSTRACT

A display module encapsulation structure and preparation method thereof, which relates to the field of display devices and can be applied in preparing AMOLED and other related display devices. The structure and method thereof mainly seals and protects the display module by utilizing the thin film encapsulation structure. That is to say, seal the display module by inorganic thin film layer which has the characteristics of transparency as well as water-resistance oxygen, buffer the internal and external stress of the thin film layer by preparing the organic module outside to the inorganic thin layer, and restrain the film layer falling off caused by the bending stress when making flexible devices. The thin film encapsulation instead of fit encapsulation can effectively improve the mechanical strength of the whole display device.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to and the benefit of U.S. Provisional Application No. 62/154,866, filed on Apr. 30, 2015, the entire content of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to the field of display devices, and more particularly, to a display module encapsulation structure and the preparation method thereof.

2. Description of the Related Art

Among the display devices of an electronic device, display devices for generating a light source, such as light emitting diode (LED) or organic light emitting diode (OLED), are the key devices keeping the normal operation of the display device. But the above-mentioned electronic devices are extremely prone to be the eroded by moisture and oxygen in the external environment. Therefore, the electronic devices should be isolated and protected in order to ensure the normal operation of electronic devices.

At present, we generally fix the cover plate on the array substrate by frit so as to seal the display electronic device disposed on the array substrate; as shown in FIG. 1. in traditional display module encapsulation structure, the array substrate 11 is provided with the display module 12, the cover plate 14 is pasted on the array substrate 11 by the frit 13 so that the display module 12 is sealed.

However, as shown in FIG. 1, the mechanical strength of the sealing structure is weak because of the characteristics of the frit 13 itself and the gap between the cover glass 14 and the array base plate 11. Therefore, the package structure is extremely prone to be damaged when an external force is encountered. Especially during the service lifetime test, the sealing structure is prone to generate gap so that the destructive gas in the external environment penetrates into the sealing structure, causing the display module 12 to be eroded, and even causing the display module 12 to be damaged when an external force is encountered. In the case, the display devices can't work properly.

ASPECTS AND SUMMARY OF THE INVENTION

To solve the above technical problems, the application provides a display module encapsulation structure, comprising:

an array substrate, a surface of which being provided with a display module;

a bank structures disposed on the surface of the array substrate and placed in the periphery of the display module;

a first film layer covering the display module as well as the surface of the array substrate between the display module and the bank structures to seal the display module;

a second film layer covering the first film layer as well as part of the surface of the bank structures; and

a third film layer covering the second film layer and the bank structures, and contacting a part of the surface of the array substrate.

In a preferred embodiment, the above-mentioned display module encapsulation structure, wherein the array substrate is provided with a thin film transistor display circuit connected to the display module so as to drive the display module.

In a preferred embodiment, the above-mentioned display module encapsulation structure, wherein the array substrate is a low temperature poly substrate.

In a preferred embodiment, the above-mentioned display module encapsulation structure, wherein said display module has a light emitting surface for light emission and a backlight surface opposite to the light emitting surface; and

the backlight surface of the display module is adhered on the surface of the array substrate, the first film layer covers the light emitting surface of the display module.

In a preferred embodiment, the above-mentioned display module encapsulation structure. wherein the display module is an OLED display module.

In a preferred embodiment, the above-mentioned display module encapsulation structure, wherein the bank structures are multilayer thin film stack structures.

In a preferred embodiment, the above-mentioned display module encapsulation structure, wherein the bank structures are made from heterocyclic polymers containing imino group and benzene ring.

In a preferred embodiment, the above-mentioned display module encapsulation structure, wherein the thickness of the bank structures is larger than the sum of the thickness of the first film layer and the thickness of the second film layer.

In a preferred embodiment, the above-mentioned display module encapsulation structure, wherein the material of the first film layer and the third film layer are both inorganic materials; the material of the second film layer is organic materials.

In a preferred embodiment, the above-mentioned display module encapsulation structure, wherein the material of the first film layer is a metal oxide or silicon nitride, either has the characteristics of transparency as well as water-resistance oxygen.

In a preferred embodiment, the above-mentioned display module encapsulation structure, wherein the material of the second film layer is an acrylic resin compound which has the characteristics of buffering and transparency.

In a preferred embodiment, the above-mentioned display module encapsulation structure, wherein the material of the third film layer is silicon nitride.

The invention provides a method for preparing the display module encapsulation structure, comprising:

providing an array substrate, a surface of which being provided with a display module;

arranging bank structures on the surface of the array substrate, said bank structures being disposed in the periphery of said display module,

preparing a first film layer to cover the display module as well as a part of the surface of the array substrate between the display module and the bank structures so as to seal the display module;

forming a second film layer on the surface of the first film layer, the second film layer covering a part of the surface of the bank structures; and

preparing a third film layer covering the second film layer, the bank structures and a part of the surface of the array substrate;

In a preferred embodiment, the above-mentioned method for preparing the display module encapsulation structure further comprising preparing a thin film transistor display circuit which connects to the display module on the array substrate so as to drive the display module.

In a preferred embodiment, the above-mentioned method for preparing the display module encapsulation structure, wherein the array substrate is a low temperature poly substrate.

In a preferred embodiment, the above-mentioned method for preparing the display module encapsulation structure, wherein the display module has a light emitting surface for light emission and a backlight surface opposite to the light emitting surface; and

the backlight surface of the display module is adhered to the surface of the array substrate; the first film layer is prepared on the light emitting surface of the display module.

In a preferred embodiment, the above-mentioned method for preparing the display module encapsulation structure, wherein the display module is an OLED display module.

In a preferred embodiment, the above-mentioned method for preparing the display module encapsulation structure, wherein the bank structures are formed as multilayer thin film stack structures by an array technology.

In a preferred embodiment, the above-mentioned method for preparing the display module encapsulation structure, wherein the bank structures are made of heterocyclic polymers containing imino group and benzene ring.

In a preferred embodiment, the above-mentioned method for preparing the display module encapsulation structure, wherein the thickness of the bank structures is larger than the sum of the thickness of the first film layer and the thickness of the second film layer.

In a preferred embodiment, the above-mentioned method for preparing the display module encapsulation structure, wherein

the inorganic materials are deposited to prepare the first film layer and the third film layer; and

the organic materials are printed to prepare the second film layer.

In a preferred embodiment, the above-mentioned method for preparing the display module encapsulation structure, wherein the atomic layer deposition process is implemented to deposit the metal oxide or silicon nitride which have the characteristics of transparency as well as water-resistance oxygen to prepare the first film layer.

In a preferred embodiment, the above-mentioned method for preparing the display module encapsulation structure, wherein the ink jet printing technology is implemented to spray an acrylic resin compound which has the characteristics of buffering and transparency to prepare the second film layer.

In a preferred embodiment, the above-mentioned method for preparing the display module encapsulation structure, wherein the atomic layer deposition process, or the chemical vapor deposition process, or the plasma enhanced chemical vapor deposition process is implemented to deposit silicon nitride so as to prepare the third film layer.

The above technical scheme has the following advantages or beneficial effects:

A display module encapsulation structure and preparation method thereof can be utilized in preparing AMOLED and other related display devices as described in the application. The structure and method thereof mainly seals and protects the display module (such as OLED display module) by utilizing the thin film encapsulation structure. That is to say, seal the display module by inorganic thin film layer having the characteristics of transparency as well as water-resistance oxygen, buffer the internal and external stress of the thin film layer by preparing the organic module outside to the inorganic thin layer, and restrain the layer falling off caused by the bending stress when making flexible devices. At the same time, the bank structures formed by multilayer stack can effectively inhibit the diffusion effect of inorganic coating, and increase the number of side of the water retaining walls of thin film device, therefore the encapsulating effect is improved effectively. The bank structures formed by multilayer stack can also function as a support for the metal mask to prevent the substrate surface pattern from being damaged during the coating process. Moreover, the thin film encapsulation instead of frit encapsulation can effectively improve the mechanical strength of the whole display device.

BRIEF DESCRIPTIONS OF THE DRAWINGS

The accompanying drawings, together with the specification, illustrate exemplary embodiments of the present disclosure, and, together with the description, serve to explain the principles of the present invention.

FIG. 1 shows a general display module encapsulation structure;

FIGS. 2 to 5 show the schematic diagram of the process of preparing the display module encapsulation structure in an embodiment.

DETAILED DESCRIPTION

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like reference numerals refer to like elements throughout.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” or “includes” and/or “including” or “has” and/or “having” when used herein, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

As used herein, “around”, “about” or “approximately” shall generally mean within 20 percent, preferably within 10 percent, and more preferably within 5 percent of a given value or range. Numerical quantities given herein are approximate, meaning that the term “around”, “about” or “approximately” can be inferred if not expressly stated.

As used herein, the term “plurality” means a number greater than one.

Hereinafter, certain exemplary embodiments according to the present disclosure will be described with reference to the accompanying drawings.

A display module encapsulation structure and preparation method thereof, encapsulate the display module (such as OLED display module) configured on the array substrate by utilizing the thin film encapsulation. That is to say, seal the display module by inorganic thin film layer having the characteristics of water-resistance oxygen, cover the inorganic thin film layer by the organic thin film layer having the characteristics of buffering to buffer the internal and external stress of the thin film layer and to facilitate the produce of the flexible device. At the same time, bank structures are configured on the periphery of the display module, the bank structures inhibit the diffusion effect of inorganic layer coating, and increase the anti-water effect of the side of the thin film device. The bank structures can also function as a support for the metal mask to prevent the substrate surface pattern from being damaged during the coating process. Moreover, the thin film encapsulation instead of frit encapsulation can effectively improve the mechanical strength of the whole display device.

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown:

Embodiment 1

FIGS. 2-5 show the schematic diagram of the method for preparing the display module encapsulation structure, comprising the steps of:

first of all, referring to Figure I, implement an array process for the display devices on the basis of a substrate (such as Low Temperature Poly Silicon) to form the array substrate 21; the above-mentioned array substrate 21 can be provided with a display area and a non display adjacent to the display area. The array substrate 21 on the display area is mainly used for the adhesion and the preparation of the display devices; at the same time, a thin film transistor display circuit can be configured on or within the array substrate 21 to drive the display module that would be prepared subsequently.

Additionally, a plurality of bank structures 23 are formed on the surface of the array substrate 21 of the non display area adjacent to the display area during the array process, the bank structures 23 can be multilayer thin film stack structures; for example, the bank patterns with a certain height can be produced by exposure, film development and etching technology during the above-mentioned array process; the bank structures 23 can be strip column, band column and other shapes.

Preferably, the material of the bank structures 23 can be made from carbon (C), nitrogen (N) and oxygen (O), such as heterocyclic polymers containing imino group and benzene ring; preferably, the material of the bank structures 23 can be polyetherimide.

Secondly, the display module 22 (such as OLED display module) is attached on the display area of the array substrate 21, the display module 22 is connected to the thin film transistor display circuit, the bank structures 23 are placed to the periphery of the display module 22, and it can be used to the first and second film layer that would be prepared subsequently so as to form the structure as shown in FIG. 2; there's a certain gap between the display module 22 and the bank structures 23 (not contact with each other), that is to say, the surface of the array substrate 21 between the display module 22 and the bank structures 23 is exposed.

Preferably, the display module 22 comprises a cathode, an anode and an organic light emitting layer arranged between the cathode and the anode; meanwhile the display module 22 has a light emitting surface (the upper surface as shown in FIG. 3) for light emission and a backlight surface (the lower surface as shown in FIG. 3) opposite to the light emitting surface; the backlight surface of the display module 22 is adhered on the surface of the array substrate 21.

Subsequently, implement the thin film encapsulation process to prepare the first film layer 24, the second film layer 25 and the third film layer 26, the procedures are as follows:

Implement the atomic layer deposition (ALD) process to deposit inorganic materials such as AlOx, SiNx, TiO2, so as to form a inorganic thin film layer which has the characteristics of transparency as well as water-resistance oxygen, therefore the first film layer 24 is formed. The first film layer 24 covers the exposed surface of the display module 22 as well as the surface of the array substrate 21 exposed between the display module 22 and the bank structures 23 (the first film layer 24 is covered in a region of the display module 22 defined by the bank structures 23, and is not extended to the area of the display module 22 on the side far away from _(t)he bank structures 23).

Preferably, alumina can be chosen to prepare the inorganic thin film layer with 300˜500 angstroms thickness for better sealing and transparent characteristics of the first film layer 24; meanwhile, the inorganic thin film layer can be contacted with a small portion of the bank structures 23 while covering the exposed surface of the array substrate 21.

Then spray the organic materials such as acrylic resin compound through the process, for example ink jet printing (IJP), to form the organic thin film layer, namely the second film layer 25, on the first film layer 24, the second film layer 25 plays the role of encapsulating the defect particles to reduce the DP issue, eliminating stress to enhance the mechanical strength of the display device, improving the smoothness of the first film layer 24 (similar to the function of the flat layer) and so on; preferably, the thickness of the second film layer 25 can be selected in the range of 15000˜20000 angstroms, so that the second film layer 25 has the above-mentioned effect of reducing DP issues, eliminating stress, improving smoothness and so on,

It should be noted that, the second film layer 25 doesn't contact with the array substrate 21, and the second film layer 25 can only cover a part of the surface of the bank structures 23, to the side adjacent to the display module, that is, the top surface of the bank structures 23, the surface of the side away from the display module of the bank structures 23 and a part of the surface of the side adjacent to the display module of the bank structures 23 are all exposed; that is to say, the height of the bank structures 23 (along the vertical direction of the light emitting surface of the display module, as shown in FIG. 5) is larger than the sum of the thickness of the first film layer 24 and the thickness of the second film layer 25 (along the direction of the light emitting surface of the display module, as shown in FIG. 5).

At last, deposit inorganic materials such as SiNx, AlOx, SiOx etc. through processes, for example chemical vapor deposition (CVD), atomic layer deposition (ALD), plasma enhanced chemical vapor deposition (PECVD) and so on, to form a inorganic thin film layer, namely the third film layer 26, which covers the surface of the second film layer 25 as well as the exposed surface of the bank structures 23. The third film layer 26 encapsulates the bank structures 23 while covering the surface, outside of and closed to the bank structures 23, of the array substrate 21.

It should be noted that, the third film layer 26 contacts with the array substrate 21, and can cover not only the exposed surface of the second film layer 25 and the exposed surface of the bank structures 23, but also a part of the surface of the side, on which the bank structures 23 is away from the display module 22, of the array substrate 21(namely the non display area). Therefore, the thin film encapsulation structure composing of the first film layer 24, the second film layer 25 and the third film layer 26 are encapsulated by the bank structures.

Preferably, alumina can be chosen to prepare the inorganic thin film with 5000˜10000 angstroms thickness for better water-resistance oxygen and film thickness of the third film layer 26; that is to say, the third film layer 26 crosses over the bank structures 23 while covering the surface of the second film layer 25 and the surface of the non display area of the array substrate 21.

In this embodiment, after the preparation process of the thin film encapsulation structure (namely the first film layer 24, the second film layer 25, the third film layer 26), the device structures that are used to form the cover glass of the display device can be pasted and fixed on the thin film encapsulation structure, so that the preparation process of the display device is accomplished.

In this embodiment, due to the water-resistance oxygen characteristic and excellent light transmittance of the inorganic films (the first film layer 24 and the third film layer 26), the display device can be effectively sealed and isolated without being damaged by water, oxygen and the other corrosive gases: and the organic thin film (the second film layer 25) placed between the inorganic film layers can effectively buffer the external and internal stress; meanwhile, the bank structures encapsulated by the thin film encapsulation structure can inhibit the diffusion of inorganic coating while supporting the entire display device. Therefore, the display module encapsulation structure and the display device, which are both prepared on the basis of the embodiment, have excellent sealing performance and a strong whole mechanical strength and flexibility.

Embodiment 2

On the basis of the above embodiment 1, as shown in FIG. 5, this embodiment provides a display module encapsulation structure, the display module encapsulation structure can be used to prepare all kinds of display devices (such as OLED display device), the display module encapsulation structure comprising:

an array substrate 21, being the substrate with the array process, may include but not limited to LTPS substrate, etc.; the array substrate 21 has a front surface (namely the upper surface, as shown in FIG. 5) and a lower surface opposite to the upper surface (namely the bottom surface, as shown in FIGS. 5 and 6); the material of the substrate can be glass. The array substrate 21 can also be formed by a hard substrate or a flexible substrate. Within the array substrate 21, or on the array substrate 21, can be arranged a driving circuit for driving the display module to emit light.

Additionally, the array substrate 21 is configured with a display area used for arranging the display device structure and a non display area adjacent to the display area. On the front surface of the display area of the array substrate 21, a display module 22 (such as an OLED display module) is configured, the display module 22 has a light emitting surface (namely the upper surface, as shown in FIG. 5) for light emission and a backlight surface (namely the lower surface, as shown in FIG. 5) opposite to the light emitting surface, is provided. The backlight surface of the display module 22 is adhered on the front surface of the array substrate 21.

Preferably, the OLED display module 22 can be an organic light emitting (OLED) module or the other kinds of light emitting modules, such as a cathode and an anode and a light emitting layer arranged between the cathode and the anode. The display module 22 is connected to the driving circuit.

Meanwhile, multilayer thin film stack bank structures 23 (such as the bank structures with the shape of strip column or band column) are provided on the front surface of the array substrate 22; additionally, the bank structures 23 can be bank patterns with a certain height, by utilizing exposure, film development and etching technology during the array process. The bank structures 23 can be disposed in the periphery of the display module. The material of the bank structures 23 can be hard materials including carbon (C), nitrogen (N) and oxygen (O), such as heterocyclic polymers containing imino group and benzene ring; preferably, the material of the bank structures 23 can be polyetherimide.

The first film layer 24 covers the exposed surface of the display module 22 and the exposed surface of the array substrate 21 between the display module 22 and the bank structures 23, so that the display module 22 is sealed. The first film layer 24 can be a inorganic thin film layer, the material of which can be inorganic materials such as SiN_(x), AlO_(x), TiO_(x) etc., the inorganic materials have excellent water-resistance oxygen and transparency. For example, the first film layer 24 can be a alumina thin film with 300˜500 angstroms thickness, and the first film layer 24 contacts with the surface of the array substrate 21 (accordingly, a gap is formed between the bank feature 23 and the display module 22, and the first film layer 24 is filled and covered on the surface of the array substrate 21 exposed by the gap).

The second film layer 25 covers the exposed surface of the first film layer as well as a part of the surface of the bank structures. The second film layer 25 can be the thin films made of organic materials, such as acrylic resin compound, and it has the effect of encapsulating the defect particles to reduce the DP issue, eliminating stress to enhance the mechanical strength of the display device, improving the smoothness of the first film layer 24 (similar to the function of the flat layer) and so on. However the second film layer 25 (the thickness of it can be 15000˜20000 angstroms) is blocked by the bank feature 23 and can not be in contact with the array substrate 21. The thickness of the bank feature 23 is larger than the sum of the thickness of the first film layer 24 and the thickness of the second film layer 25.

The third film layer 26 covers exposed surface of the second film layer 25 and the exposed surface of the bank feature 23 and the surface, adjacent to the bank feature 23 and away from the side of the display module 22, of the array module 21. The third film layer can be inorganic material thin film such as SiN_(x), AlO_(x), SiO_(x), and can encapsulate the bank feature 23 on the front surface of the array substrate 21 together with the first film layer 24 and the second film layer 25.

Preferably, the material of the third film layer can be SiN film with 5000˜10000 angstroms thickness, to provide the excellent sealing property of the display device.

It should be noted that, the structure provided in this embodiment can be prepared on the basis of the method recorded in the embodiment 1, so the technical features such as the preparation process, the film layer material and the positional relationships between the film layers can be applied in the structures of embodiment 1, and thus are omitted here for brevity.

Therefore, the display module encapsulation structure and preparation method thereof provided in the embodiments, encapsulates the display module directly on the substrate by means of the display module encapsulation structure formed through the thin film encapsulation process, meanwhile the display module encapsulation structure has the properties of water-resistance oxygen and buffering. Hence the display module encapsulation structure can effectively buffer internal and external stress while ensuring the sealing effect of the display module, it can avoid the falling off of the film during the preparation of flexible devices, and can also effectively buffer the external impact forces caused by the falling and collision of the display device structures after the product is finished, so that the issues such as the split or the broken of screens caused by the stress concentration generated by the external impact forces, are greatly reduced. Therefore, it improves the whole structural strength of the display device so that the yield and the performance of the display devices are greatly improved. Meanwhile, the bank structures encapsulated by the thin film encapsulation structure can inhibit the diffusion of inorganic coating while supporting the entire display device. Therefore, the display module encapsulation structure and the display device, which are prepared on the basis of the embodiment, have excellent sealing performance and a strong whole mechanical strength and flexibility.

The foregoing is only the preferred embodiments of the invention, not thus limiting embodiments and scope of the invention, those skilled in the art should be able to realize that the schemes obtained from the content of specification and figures of the invention are within the scope of the invention.

It will be obvious to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention, and therefore all changes and modifications that fall within the scope of the claims. All the changes and modifications of the claims are therefore intended to be in the range of the invention. 

What is claimed is:
 1. A display module encapsulation structure comprising: an array substrate, a surface of which being provided with a display module; a bank structures disposed on the surface of the array substrate and placed in the periphery of the display module; a first film layer covering the display module as well as the surface of the array substrate between the display module and the bank structures to seal the display module; a second film layer covering the first film layer as well as a part of a surface of the bank structures; and a third film layer covering the second film layer and the bank structures, and contacting a part of the surface of the array substrate.
 2. The display module encapsulation structure as disclosed in claim 1, wherein the array substrate is provided with a thin film transistor display circuit connected to the display module so as to drive the display module.
 3. The display module encapsulation structure as disclosed in claim 2, wherein the array substrate is a low temperature poly substrate.
 4. The display module encapsulation structure as disclosed in claim 1, wherein the display module has a light emitting surface for light emission and a backlight surface opposite to the light emitting surface; and the backlight surface of the display module is adhered on the surface of the array substrate, the first film layer covers the light emitting surface of the display module.
 5. The display module encapsulation structure as disclosed in claim 1, wherein the display module is an OLED (Organic Light Emitting Diode) display module.
 6. The display module encapsulation structure as disclosed in claim 1, wherein the bank structures are multilayer thin film stack structures.
 7. The display module encapsulation structure as disclosed in claim 6, wherein the bank structures are made from heterocyclic polymers containing imino group and benzene ring.
 8. The display module encapsulation structure as disclosed in claim 1, wherein a thickness of the bank structures is larger than a sum of a thickness of the first film layer and a thickness of the second film layer.
 9. The display module encapsulation structure as disclosed in claim 1, wherein material of the first film layer and the third film layer are inorganic materials; material of the second film layer is organic materials.
 10. The display module encapsulation structure as disclosed in claim 9, wherein the material of the first film layer is a metal oxide or silicon nitride, either one has the characteristics of transparency as well as water-resistance oxygen.
 11. The display module encapsulation structure as disclosed in claim 9, wherein the material of the second film layer is an acrylic resin compound which has the characteristics of buffering and transparency.
 12. The display module encapsulation structure as disclosed in claim 9, wherein the material of the third film layer is silicon nitride.
 13. A method for preparing the display module encapsulation structure, wherein the method comprising the steps of: providing an array substrate, a surface of which being provided with a display module; arranging bank structures on the surface of the array substrate, said bank structures being disposed in the periphery of said display module, preparing a first film layer to cover the display module as well as a part of the surface of the array substrate between the display module and the bank structures so as to seal the display module; forming a second film layer on a surface of the first film layer, the second film layer covering a part of a surface of the bank structures; and preparing a third film layer covering the second film layer, the bank structures and a part of the surface of the array substrate.
 14. The method for preparing the display module encapsulation structure as disclosed in claim 13, further comprising: preparing a thin film transistor display circuit which connects to the display module on the array substrate so as to drive the display module.
 15. The method for preparing the display module encapsulation structure as disclosed in claim 14, wherein the array substrate is a low temperature poly substrate.
 16. The method for preparing the display module encapsulation structure as disclosed in claim 13, wherein the display module has a light emitting surface for light emission and a backlight surface opposite to the light emitting surface; and the backlight surface of the display module is adhered to the surface of the array substrate; the first film layer is prepared on the light emitting surface of the display module.
 17. The method for preparing the display module encapsulation structure as disclosed in claim 13, wherein the display module is an OLED display module.
 18. The method for preparing the display module encapsulation structure as disclosed in claim 13, wherein the bank structures are formed as multilayer thin film stack structures by an array technology.
 19. The method for preparing the display module encapsulation structure as disclosed in claim 13, wherein the bank structures are made of heterocyclic polymers containing imino group and benzene ring.
 20. The method for preparing the display module encapsulation structure as disclosed in claim 13, wherein a thickness of the bank structures is larger than a sum of a thickness of the first film layer and a thickness of the second film layer.
 21. The method for preparing the display module encapsulation structure as disclosed in claim 13, wherein in the method: the inorganic materials are deposited to prepare the first film layer and the third film layer; and the organic materials are printed to prepare the second film layer.
 22. The method for preparing the display module encapsulation structure as disclosed in claim 21, wherein in the method: the atomic layer deposition process is implemented to deposit a metal oxide or silicon nitride which has the characteristics of transparency as well as water-resistance oxygen to prepare the first film layer.
 23. The method for preparing the display module encapsulation structure as disclosed in claim 21, wherein in the method: an ink jet printing technology is implemented to spray an acrylic resin compound which has the characteristics of buffering and transparency to prepare the second film layer.
 24. The method for preparing the display module encapsulation structure as disclosed in claim 21, wherein in the method: an atomic layer deposition process, or an chemical vapor deposition process, or a plasma enhanced chemical vapor deposition process is implemented to deposit silicon nitride so as to prepare the third film layer. 